It is known to mount a discharge hood over the open top of a rectangular container and then to invert the container to discharge the container contents. In the known arrangements it was necessary to remove the container lid or lid assembly to allow the hood to be mounted on the container. This involved considerable physical effort due to the large size of lids required for commercial size containers which are approximately 1200 mm cube. Some efforts have been made to alleviate the problem by making the lid in two pars, but the two lid parts were still heavy for one man handling and still had to be removed in order to mount the hood.